[PATCH 1/2] mailbox: zynqmp-ipi: Fix CPU hotplug state cleanup

[Prasanna Kumar T S M <ptsm@linux.microsoft.com>]

On driver removal, the CPUHP_AP_ONLINE_DYN CPU hotplug state is removed
instead of the its actual state. This can leave the mailbox driver
callbacks dangling. Use the actual CPU hotplug state during driver
removal.

Hotplug registration failures are also ignored, allowing probe to
succeed without the callbacks needed to enable interrupts on CPUs
brought online later.

Fixes: 6ffb1635341be ("mailbox: zynqmp: handle SGI for shared IPI")
Signed-off-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
---
 drivers/mailbox/zynqmp-ipi-mailbox.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index 42d2583e44ca..b0643ee75db0 100644
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -136,6 +136,7 @@ struct zynqmp_ipi_pdata {
 	unsigned int method;
 	u32 local_id;
 	int virq_sgi;
+	enum cpuhp_state hp_state;
 	int num_mboxes;
 	struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
 };
@@ -863,15 +864,22 @@ static int xlnx_mbox_init_sgi(struct platform_device *pdev,
 	irq_set_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
 
 	/* Setup function for the CPU hot-plug cases */
-	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mailbox/sgi:starting",
-			  xlnx_mbox_cpuhp_start, xlnx_mbox_cpuhp_down);
+	pdata->hp_state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+			  "mailbox/sgi:starting", xlnx_mbox_cpuhp_start,
+			  xlnx_mbox_cpuhp_down);
+	if (pdata->hp_state < 0) {
+		irq_clear_status_flags(pdata->virq_sgi, IRQ_PER_CPU);
+		free_percpu_irq(pdata->virq_sgi, &per_cpu_pdata);
+		irq_dispose_mapping(pdata->virq_sgi);
+		return pdata->hp_state;
+	}
 
 	return ret;
 }
 
 static void xlnx_mbox_cleanup_sgi(struct zynqmp_ipi_pdata *pdata)
 {
-	cpuhp_remove_state(CPUHP_AP_ONLINE_DYN);
+	cpuhp_remove_state(pdata->hp_state);
 
 	on_each_cpu(xlnx_disable_percpu_irq, NULL, 1);
 
-- 
2.49.0